Telephone switching and signaling apparatus.



- I PATENTED OCT. 23, 1906. I .J. G. WRAY, H. T. GARDNER & w. G. KINTDN.

TELEPHONE SWITCHING AND SIGNALING APPARATUS;

APPLIOATION FILED MAR-.12, 1906.

NMN

51" ozwtow v 'No. 833,817. PATENTED 0012s, 1906. J. G. WRAY, H. T. GARDNER & w. G. KINTON. TELEPHONE SWITCHING AND SIGNALING APPARATUS.

APPLICATION FILED MAR.12,1906.

I c ln-uowtou atkoznup',

1 I rinirnn sra rns rarnnrg osnronf JAMES o; WRA'Y, or CHlOAGO, HERBERT r. GARDNERQOFI MAYWOOD,

TON, residing at selectively signaled AND. WlLLlAll i QT. KINTON,

, TION OF NEW YORK.

To all whom. it mag/concern.-

Be'it' known that we, JAMES G. WRAY, residing at Chicago, HERBERT T. GARDNER, residing at Maywood, and WiLLiAM G. K1N-- Chicago, in the county of Cook, State of Illinois-have invented certain Improvements in Telephone Switching and Signaling Apparatus, oi which the following is 'a specification.

i The present'invention relates to a telephone-exchange apparatus, and Inc-re partilcularly toautolnatic signaling means whereby the substations of a fouuparty line may be fering with the proper signaling through the selective two-party line or a single party line.

In a prior application filed by us July 3, 1905, Serial No. 268,213, of which the present application isa division, we described a telephone-exchange apparatus in whichthe invention was expressed mainly in the ar rangement of the signal-controlling devices in the cord-circuits, being especially adapted for use in connection with trunk-lines leading from one central station to another, although certain features of the invention were described as capable of use in connection'with cord-circuits for connecting substations atthe same central station.

I In. order that the presentiuventlon may be readily understood, we llGIGWltll describe so tion constitutingthe present invention.

much of the apparatus and its mode of o erasubjectinatter of our former application above referred to as is necessaryto a proper understanding of the Briefly stated, the present invention'consists in an arrangement whereby the substa-- tions of a four-party line may be selectively signaled without, however, interfering with the proper signaling through the same arrangcn'icnt on selective twopa'rty line or on a single-party line. on the four-party line depends for its operation upon a relay located in the trunk-line cord-circuit which operates as a pole-changer to changethc direction of a pulsating signal lug-current, the said relay )eing prevented from operation by a suitable resistance in its local circuit when either of the two stations on one main circuit is connected by its spe Ripecification of Letters Eatent.

[ in said local circuit when either without, however, inter- The selective signaling OF OHlCAG-O, ILLINOIS, ASSI'GNORS TO AMERICAN 'llELEPHONE AND TELEGRAPH COMPANY, A GORPORA sienaeme APPARATUS.

Patented Oct. 23,1906.

Divided andthis application filedMaroh 12,1906. Serialllp. 305,6 58- l cial spring-jack ringing dev ces at crating to change with the switch-plug and the central station, but opthe direction of the chrrent 5 5 of the two other stations have their representative 3' acks plugged. into. The substation callfsignals on J a four-party line are in earthbranches, the signals of two of the substations being' in 60 branches to earth from one-side of the line, while those of the other two substations are in branches to earth from the opposite side of the line, and the bellsin thetwo branches on each side of the line are oppositely polarized, biased, or otherwise adjustedso'as'to 0 erate in res pohse to currents of opposite Ichrec tion, respectively. By arranging a four party line with inulti'ple jacks, therefore, there being a jack corresponding to each station on the line, and by properly arranging the jack terminals any one of the stations may be signaled by merely placing the plug at the central oliice in the jack belonging to said station. i

Figure 1 is a diagram of the circuits at the calling central station 5 and Fig. 2 is a dia gram of the circuits at the called central station, Fig. 2 also showing the jacks for one, two, and four party lines, together with the circuit connections at the substations on said lines.

It is to be understood in tracing the circuits in connection with the following description that the conductors a (L -and 1) b 8 Fig. 2, are continuations, respectively, of the conductors similarly characterized in Fig. 1, and, further, in describi-n the apparatus'and its operation the successive acts of the central-station operators and the subscribers will be followed, beginning with the part performed by the operator at the-calling subscribers central station after receiving a call for connection With a substation at another central station.

Referring to the drawin s, at substation 400, Fig. l, the subscriber desires to be connected with the subscriber at substation 500, Fig. 2, for example, The subscriber. at sub] station 400. takes down his receiver, thus 1C0 causingthe signal-lamp S to light in a manncr well understood, the circuits being those ordinarily used in the central energy telephone system. The operator at the calling .0 pressing the key A, places i necessary,

I at'another exchange,

subscribers central station then inserts the plug E in the jack E placing herself in communication with the calling subscriber and extinguishing the lamp S in the usual way. It may be assumed that the calling subscriherdesires connection with a subscriber and upon ascertaining the desires of the subscriber the operator at the central station M of the calling-line,

nication, through the conductors ai and a", with the operator at the central station N of the called line and asks the operator at that station to assign her a trunk, no signal being the operator's set. As soon as the trunk has been assigned the operator at the central station M inserts the plug B in the jack B, which is assumed to belong to the trunk assigned, thus connecting the callingsubstation, through the cord-circuit at central station M, with the trunk-line cord-circuit at the central station N through the conductors b and N. This closes a circuit through a relay 2 5 d in the cord-circuit at the central station N 5 5 ductor 10, which isconn 6o nection has of the plug which relay will be hereinafter termed-the primary signal-circuit-controlling relay and also closes circuits through the supervisory lamps at both central stations.

The circuit through the supervisory lamp F at the call-originating central station M. is the usual circuit, startingfrom the battery K and passing through conductors 2 and 3 to the sleeve B of the plug B, the frame B of the jack B to ground G and. back to ground G", thus completing the circuit through the lamp F and lighting the same. The current for the circuit through the relay 4 at the central station N is supplied from the battery l) 4.0 at said stat-ion and passes from said battery through conductorsband 7, coil of relay d, conductor Sf'and winding of inductioncoill in circuit with the conductor Ii, said conductor 1) jack-spring Bil tip-terminal B B, and ground G completing the circuit through ground G at the called central station N, which is connected with the other pole of the battery D. This energizes the re ay cl and causes the arniatures (l and thereof to be attracted.

The supervisory lamp H, Fig. '2, is included in a circuit w 'ch may be traced as follows: battery I), conductor '6, armature (l conductor 9, armature of relayf, and conposite terminal of the battery D.

So far as relates to the operator at the calling central station, nothing further .is to be done except to ascertain that the proper con been made and answered, the fact that the si nal at the called substation is in operation eing imparted to her by an audible si nal, as will be hereinafter described, while the fact that the called sub scriber has answered is imparted by the cos;

herself in commul since the connection is direct to cted with the opsation of the audible signal and by the (Ni iii-- guishing of the supervisory lamp l Furthermore, since the signaling-current lb; con trolled by the insertion of the plug al (he called central station N, there being no ii]'- cuit for said current unl il the plug is l'ully inserted, the operators at the central stations cannot under any (-ircuinstances receive shocks, as might be the case it the signaling-.: current were under the control ol' one ol the operators only. hlOIOOVt-ll, th relay d eontrols a switch in the signaling-eireuit, said switch being closed when. the said relay is energized, so that it is i'i'npossible tor a signal to be sent out over the ialled line until the op erator at the calling central station has made connection with the trunk-line. ll, .herw tore, she has taken the wrong trunk by mistake, the subscriber will not be aceidentallll' called.

Assuming that the oporal or at the central station N has placed the plug t, in the inch C", which belongs to station 501), and that the operator at the calling-staiion )1 has inserted the plug in the jack, producing the condition above described, and presmning, further, that the bell at substation too is arranged to respond to plus current lrom the generator, the circuits controlling the signal at 500 may be traced as follows: in the first place, theinsertion oi the plug in the inch a circuit through the relay f from the battery D through thcconduetor 5, conductor 12, relay g, (the function and opera tion ol which will be hereinafter descrihedd coil of relay f, sleeve L, frame conductor l3, cut-oil relay h, conductor 14, and grounds G and G to the other terminal of the battcry D, This energizes the relay f, attracting the armaiuresf andf, which are shown as being connected together, and the armature f, which cuts out the ordi'. ary busytcsr circuit consisting ol' the conductor 15, induction-coil ll, the operntons receiver 'l, and ground G 'lhe relays g and f both having been energized, the signalingwircuit is completed and may be traced as follows: Starting from the positive terminal of the generator Z the current passes through eondnctor 16 to armature g and conductor l7, (which includes the principal winding e of the double-coil relay o,l the armature y, ils forward contact-point, conductor H1, :llllll1-- turo (l conductor 19, armature e", condiuloi' 20, armature r' nductor ll, ring-terminal C of the switeh- 'ilug, long spring W", (onductor 22, through the condenser and bell at station. Sill), conductor 23, spring (7, tip--lei'- ininal coinluctor Z l, armature f, conductor 2.), and the induction-coil \i'indings 5i therein to eoi'ulm't rilli, ronduciorl'i, and conductor to the other brush ol the generator, thus completing the generutoneircuit and causing the bell to ring. At the breaks the circuit containing the supervisory lamp'H, so that the saidsupervisory lamp is I .s 'jcoil windin sext ished. As ereinbefore stated one of the induction- 51 is included in the generatorcircuit,so t at the induced current in its associated winding 50 produces an audible si 'n'al 1n the receivers at the calling subscriber s central station and substation,

indicating substation is thus obv ating the necessity on that the si nal at the called ringing, and

-' the part of the operatoi at the calling central station M of requesting "another ring if the called subscriber does not promptly answer. The ringing Will continue until the called subscriber takes down his receiver to an -swer,. and the taking down of the receiver short-circuits the condenser and bell at his station and by cutting out the resistance thereof admits of suflicient increase of generator-current over the circuit to energize the armature c coil 0 armaturele",

the coil e of the relay 6 to such an extent that At the same.time.:thearping the signal.

attracted, closing a circuit mature if is maintain the armatures attracted, although insufficient to attract then; in the first place. I from the battery 1) through the conductor 5, 30, armature f and conductor back to the other terminal of battery D. The closing of the circuit through the armature 6-- also completes the line or talking circuit through theinduction-coiland the telephone i at the called substation 500, the said circuit central station M.

ncludes the relay 7"" of the callingwline, the armature j of Which includingthe relay 7', so as to attract the armature 7 thereof, thereby closing a circuit which controls the operation of the supervisory lam F at the calling subscribers The circuit thus closed is from the battery K to rin --terminal B of plug 'B and line conductor 2 through windconductor 3i, armaitsforward contact, conductor 32, and conductor 10..to ground G and back to the battery K through ground G This circuit at the central station M tral station N through when attracted closes a shunt around the lamp F, extinguishing the s'ame,-and thus withdrawing t 1e signal and indicating that the wantedsubscriber has responded to the call. Thus when the called subscriber has finished conversation aid hasreplaced his receiver, breaking the conductive connection. round the condenser, consequently opening the main metallic circuit, the relay 7' at the central station N will become deenergized, breaking the circuit thus traced and causing the armature 1 at the call-originating central station M to drop back and open the s will be attracted, breaking.

the generator-circuit at that point and the energizing 'efl'ect of This circuit passes conductor 29, conductor shunt around the lamp F, so that the lamp F lights. Since, however, the supervisory lamp H is controlled, as previously stated, through the operation of the I centralstation M, said lamp will not belighted until the operator there has removed her switch plug B, so that the supervision of the line is Wholly under the control oi one operator.

The removal of the i socket B at the central station M pursuant relay 6 to become deenergized, thus estab lishing a circuit through the lamp H from battery D through conductor 6, armature d and its back contactconductor 30, arma lamp ii being broken by the armaturef of relayf "Q In signalinga two-party line the operation issubstaritially the same as above described,

both. of which are arranged t v plus current from the generator, are branched to ground-iron] opposite sides of the line, and the line is provided With'two jacks, one for each station, the long spring of one jack connected to one side of the line and the. long spring, of the other jack being connected to the opposite side of the line. If, for example, it is desired to call station-number 50] the plug is inserted in jaclr50l the ring--termii'ial 0 thus being connected with the line conductor 23*. The circuit from the generator Z is then. as follows: conductor 16, armature g conductor 17, ductor l8, armature d conductor 19, armz ture e, conductor 20, armaturef conductor 21, ring C long spring of jack 501, line conductor 23, and the condenser and bell at station 501 to the ground, and thence back from the ground G through the conductors 26 and 27 to the other brush of the generator 74. In this case, as in the one-party line, the generator-current is stren thened by shortcircuiting the condenser When taken down, thus giving the necessary increase in current to attract the arn'iature e and stop the signal.

What has be n described above relating to automatic signal-controlling devices is. not herein specifically claimed, as the same forms plug at the saidplug B from the su itch to the appearance of the signal F causes the being The i plug 0 from the jack C restoring all the parts to their I normal condition, "the circuit through the stopexcept that the bells at the two substations, 0 respond to armature g con- IIO the receiver is the subjectmatter of our application Serial be had to the means for the agency oi an electron]agnctic nolewha tions 503 and 505 1n afounperty lino two of the suhstations are provided with bells which are arranged to respond to minus currents from the generm tor and the other two substations with bells which are arranged to respond to pliili rents, one plus bell and one minus belllh each in an independent earth branch lrdni each side of the line the operation of the two bells of the same character, but connected with diflerent line conductors, being con-- trolled by the arrangement of the jar-hie, us de scribed in connection with the two-n I line. The two bells on this circuit which a e arranged to onerote in. response to plus currents from the generator are operated 6X:- actly as in the two-perty line above described, the circuits beingthe some. in order to separate the minus bells, however, it is necessary to change the direction of the current coining lroin the generator at "he central o'l'lice, and this is accomplished through ing switch, herein shown as embodied in th relay 9 in connection with a relay included in series with the cut-oil relay h in the jaclc frame of the plug-sleeve conductor-circitit ol the two spri11g-jacks representing the two stations hiwing the minus bells. The relay 9 is so wound that when the additional resistance above referred to is in series therewith it will not become sulllcicntly energized to attract the immatures g and so that the said srmetureswill renuiin. in the position shown in Fig. thus causing the minus side oi the generator to he connected in circuit through the conductor us arms t re ductor 1?, armature g", conductor l8, 330., the remainder of the circuit bei the some as previously traced in connection with. the plus side of the generator. Referring; to the illustration ol the four party line in. Fig. L, the bells at the substasre arranged to operate in. response to ylus current from the generator, the frames oi the ja'clrs .5625 and 505 heir directly connected to the cut-oll'rcla'y conductor 13, as in the one and two party lint-s. The frames of the jacks 594- and Silo, corn spending to the stations 50 i and 506, the bells of which. ere adapted to operr sponse to current pulsations ol? minus sign or direction, are connected with a conductor 13, which passes through the coils oi :1 special relay to the conductor 12:3, relay 1; conductor l t, to the ground, cs hclorc. in this case, therefore, the coils ol relay it are includ ed in circuit with the soils ol? the who 5 the latter being so urran l or 1 not to respond to current ouuini: resistance 05 the ro l It", "while so arranged or fit jus d as to respond whether this sir-Amine is in the circuit or not. Assure low that the operator at l, as placed the plug U in t jack-506, Whieh belongs to station 596, with l battery.

a minus hell on the four-party line and that the operator at the calling-station M has inserted the plug in the jack assigned to her, the signal is given substation 506, will now he described. Under the conditions m ned whore role is holding its nrrnatures d 4" against their iorws "d contacts. Relay f likewis is holding it arniaturesf, f and j' finalist their n lord rrvon rcts, wherms relay 5; does not attract its arinzitures g g heceus' e ol the res ;tanoe of the relay in, included in series with the cut-oll relay it in the izicsr'l'rcme oi: the phi: leere-conductor circu ol' the two spring-jocks 504- 506", represwting the two stations liming the minus bells. 'lhc circuits cmitrolliu the signal traced as follows: St: Inga from the may be negative terminal ol the generator Z, the current passes tlnough conductor 26 to the on nurture 9, though conductor 17, including the principal winding e of the double-coil relay c, to armature 9", its forward contact, cmu'luctor 1E5, rniature 1, conductor 19, are e, com'luctor Kl, zn'nutture f, conductor Zl ring-terminal plug, long); spat of spring inch 506, and thei'rce along the liln--wire-aurl through minus itzuice at sullen 506 to ground,

generator I through ground G 2 l and 7 Wl'ienjho celled subrespecting sigonc minus hell on one side ol the .in eqn applies to the minus hell on the OlT POSll'Q side ol the due, it or 5' being nor-les sorv to insert the plu into the spring-jack r wesuondlug to the ration he ring the other The operation ol" signaling with the plus bells is similar to the t described in connection with one and two party lines and ds no further rmplanation.

inlay when desired provide m ans or u'niintaining an additional llow ol current through the coils of the cutotl' relay 71. when the circuit thereof includes the res mice ol" the special relay Ir, and for this purpose the arnmture k ol' the relay [4: is arranged to close a circuit th ough the conductorfill containing; the res Lance 125 ll, conductors 13", 113, d (3, the current then passing from the hat trr'y U ov r the conductors (l 13, etc, and tire armature It to the conductor 13, relay h, and coinhzctm' 14 to the ground (,l and g ound Under these circumstances the cutofi relay li receives current through thdplugcircuit and special relay 7c and also byway of conductor 13'.

' It will be noted that the bells in connectioniwith fourparty lines are connected directly from the line to the ground through a'resistance instead of being connectedthroughcon- 'densers. The'additional generator-current, which is necessary to energize the relaye upon the removal of the receiver, is caused by including the two sides of the line in the generator-circuit when the receiver has been removed, one brush of the generator being connected with the ring of the plug, While the other brush is connected with the tip.

The connectionscontrolled by the armaturesfg and g are such that the same terminal o a brush of the generator, whether the current tion or the other.

is flowing over the signal-circuit in one direc- Consequently'in any case the flow of current through the coil 6 is in the same direction as the flow of current through the coil e so that the magnetization caused by the flow of current through one coil will harmonize with that caused by the flow of current through the other.

It is to be understood, of course, that the drawing is a conventional illustration of the system, the relays being shown where the control of two or. more circuits is involved as provided with two or more armatures. In

practice each relay maybe and usually is- "provided witha single armature adapted to g for the control of the several circuits.

actuate such contacts as may be necessary In order to' avoid any possibility of misunderstanding, it may be stated that thelowerchanging switch to control said means; cirmost jack E of each set of jacks shown in the drawings is the answering-jack for the line to which it belongs, the operation of said answering-jacks not being referred to except in connection with the calling substation 400,

A Fig. 1, since no novelty is involved, the jacks being shown simply to complete the illustration of the system in general.

- 1. In a.tele'phon.e signaling system for selectively signaling the substations onfourparty-lines, a plus bell and ,a minus bell-in separate earth branches from each side of the line; a call-current generator; means for conjnecting one terminal of said generator to either side of the line, and the other terminal thereof to earth; an electromagnetic polecuits to control said pole-changing switch "corresponding respectively to the substationson the line; and means for introducing he coile is connected to the same resistance in two of said circuits to reduce the current and prevent the operation of said pole-chang1ng switch.

2. In a telephonesignaling system for selectively signaling substations on four-party lines, a plus bell and a minus bell in separate earth branches from each side of the line; a call-current generator; an electromagnetic pole-changing switch. for connecting one terminal of sa1d generator to either side of the line, and the-other terminal thereof to earth;

circuits to control said pole-changing switch,

one for each substation on the line; andone or more relays n two of said circuits, the resistance oi which is sufficient to pervent the operation of said switch.

' 3. In a telephone signaling system for se lines, a plus bell and a minus bell in separate earth branches from each side of the line; a call-current generator; an electromagnetic pole-changing switch for connecting one terminal of said generator to either side of the line, and the other terminal thereof to earth; circuits to control said pole-changing switch, one for each substation on the line; one or more relays in two of said circuits, the resist ance of which is suificient to prevent the operation. of said switch; means for closing circuits through said switch, said circuits corresponding respectively to the several substations and also passing through the coils of the cut-off relay; a circuit-controlling arma- .ture operated by said relay; and a separate circuit controlled by said relay and. passing through the winding of the cut-ofl relay.

4. In a selective signaling system, a callcurrent generator; an electromagnetic 'pole changing switch therefor; a generator-circuit in which the direction. of llow of current from said generator is determined by said polechanging switch; a circuitbreaker for said circuit; a relay in the generator-circuit controlling said circuit-breaker; and circuitcontrollers -operatcd by said polechang1ng lectively signaling substations on four-party IIC 

